From: Klaus Jensen <k.jensen@samsung.com>

Protection Information can only be enabled if there is at least 8 bytes
of metadata.

Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
---
 hw/block/nvme-ns.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/block/nvme-ns.c b/hw/block/nvme-ns.c
index 7f8d139a8663..ca04ee1bacfb 100644
--- a/hw/block/nvme-ns.c
+++ b/hw/block/nvme-ns.c
@@ -394,7 +394,7 @@ static int nvme_ns_check_constraints(NvmeNamespace *ns, Error **errp)
         return -1;
     }
 
-    if (ns->params.pi && !ns->params.ms) {
+    if (ns->params.pi && ns->params.ms < 8) {
         error_setg(errp, "at least 8 bytes of metadata required to enable "
                    "protection information");
         return -1;
-- 
2.31.0

On Wed, Mar 24, 2021 at 09:09:01PM +0100, Klaus Jensen wrote:
>From: Klaus Jensen <k.jensen@samsung.com>
>
>Protection Information can only be enabled if there is at least 8 bytes
>of metadata.
>
>Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
>---
> hw/block/nvme-ns.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/hw/block/nvme-ns.c b/hw/block/nvme-ns.c
>index 7f8d139a8663..ca04ee1bacfb 100644
>--- a/hw/block/nvme-ns.c
>+++ b/hw/block/nvme-ns.c
>@@ -394,7 +394,7 @@ static int nvme_ns_check_constraints(NvmeNamespace *ns, Error **errp)
>         return -1;
>     }
>
>-    if (ns->params.pi && !ns->params.ms) {
>+    if (ns->params.pi && ns->params.ms < 8) {
and also it is good check that "metadata size" is power of 2 or not?

>         error_setg(errp, "at least 8 bytes of metadata required to enable "
>                    "protection information");
>         return -1;
>-- 
>2.31.0
>
>

On Mar 29 19:52, Gollu Appalanaidu wrote:
> On Wed, Mar 24, 2021 at 09:09:01PM +0100, Klaus Jensen wrote:
> > From: Klaus Jensen <k.jensen@samsung.com>
> > 
> > Protection Information can only be enabled if there is at least 8 bytes
> > of metadata.
> > 
> > Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
> > ---
> > hw/block/nvme-ns.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/hw/block/nvme-ns.c b/hw/block/nvme-ns.c
> > index 7f8d139a8663..ca04ee1bacfb 100644
> > --- a/hw/block/nvme-ns.c
> > +++ b/hw/block/nvme-ns.c
> > @@ -394,7 +394,7 @@ static int nvme_ns_check_constraints(NvmeNamespace *ns, Error **errp)
> >         return -1;
> >     }
> > 
> > -    if (ns->params.pi && !ns->params.ms) {
> > +    if (ns->params.pi && ns->params.ms < 8) {
> and also it is good check that "metadata size" is power of 2 or not?
> 

While I don't expect a lot of real-world devices having metadata sizes
that are not power of twos, there is no requirement in the spec for
that.

And the implementation here also does not require it :)

On Tue, Mar 30, 2021 at 09:24:59AM +0200, Klaus Jensen wrote:
>On Mar 29 19:52, Gollu Appalanaidu wrote:
>> On Wed, Mar 24, 2021 at 09:09:01PM +0100, Klaus Jensen wrote:
>> > From: Klaus Jensen <k.jensen@samsung.com>
>> >
>> > Protection Information can only be enabled if there is at least 8 bytes
>> > of metadata.
>> >
>> > Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
>> > ---
>> > hw/block/nvme-ns.c | 2 +-
>> > 1 file changed, 1 insertion(+), 1 deletion(-)
>> >
>> > diff --git a/hw/block/nvme-ns.c b/hw/block/nvme-ns.c
>> > index 7f8d139a8663..ca04ee1bacfb 100644
>> > --- a/hw/block/nvme-ns.c
>> > +++ b/hw/block/nvme-ns.c
>> > @@ -394,7 +394,7 @@ static int nvme_ns_check_constraints(NvmeNamespace *ns, Error **errp)
>> >         return -1;
>> >     }
>> >
>> > -    if (ns->params.pi && !ns->params.ms) {
>> > +    if (ns->params.pi && ns->params.ms < 8) {
>> and also it is good check that "metadata size" is power of 2 or not?
>>
>
>While I don't expect a lot of real-world devices having metadata sizes
>that are not power of twos, there is no requirement in the spec for
>that.
>
>And the implementation here also does not require it :)

Reviewed-by: Gollu Appalanaidu <anaidu.gollu@samsung.com>